cerium (n.)

metallic element, first isolated in pure form in 1875, named for ceria, the name of the earth from which it was taken, which was discovered in 1803 and named by Berzelius and Hissinger for Ceres, the minor planet, "whose discovery (in 1801) was then one of the most striking facts in physical science" [OED]. The planet was named for the Roman goddess Ceres, from a root meaning "to grow." With metallic element ending -ium. Related: Ceric.